Thanks partly to Boeing's new jet factory, Snohomish County, Wash., is one of the fastest-growing counties in the country. The north Seattle county's energy demand is expected to increase 25 percent over the next decade, and its local utility is scrambling for new sources of power.

Currently, the Snohomish County Public Utility District gets 80 percent of its energy from massive dams on the Columbia River. But with big dams and fossil fuels losing favor, it's looking to alternative sources: solar, wind, geothermal and biomass and, perhaps the most controversial of all, small-scale dams, which utility managers consider environmentally and economically viable.

Boosters tout small-scale hydroelectric projects -- defined as generating less than 30 megawatts, or enough to power up to 30,000 homes -- as carbon-neutral and more fish-friendly. And the resource has staggering potential: Just a fraction of the possible sites on Washington's waterways could power millions of homes.

But although utilities, investors and speculators are getting into the game, small-hydro development won't be easy or cheap without policy incentives and tax credits. And not everyone thinks it's a good idea. "We look at our watersheds and waterways in the Northwest as pretty stressed already. The impacts are apparent everywhere," says Rich Bowers, Northwest coordinator for the Hydropower Reform Coalition, a network of 140-plus environmental and outdoor recreation groups.

Snohomish PUD will build its first small-hydro project on Youngs Creek near Sultan, Wash. The 7.5-megawatt, $30 million plant and its successors will be "run-of-the-river" works, which use dams less than 15 feet high, and rely on natural streamflows and grade to generate electricity (instead of engineering stronger flows and a higher grade, as conventional dams do). Youngs Creek lacks salmon and recreational activity, so the environmental and boating-advocacy group American Whitewater and other groups have dropped their initial objections.

The Youngs Creek project demonstrates the potential upside of small hydro. Migrating fish can usually bypass or swim up small dams, and water quality and temperature aren't greatly affected because there's no deep reservoir. Small hydro has virtually no carbon output, and it represents a local and distributed power base. And Snohomish PUD -- which expects to have a list of 10 preferred small hydroelectric projects out this summer -- plans to meet certification through the Low Impact Hydropower Institute (LIHI), the hydroelectric equivalent of the LEED program for "green" building.

Whether or not they're certified green, however, the potential proliferation of new dams worries most environmentalists. "These small projects in many cases have the biggest impacts relative to their size," says American Whitewater's Thomas O'Keefe.

New projects often use "weirs," low dams that allow water to spill over the top, but O'Keefe says such structures still de-water streams to turn turbines, thereby annihilating boating runs. And even small projects require habitat-disturbing transmission lines and maintenance roads. One plant on a salmon-free creek might be OK, but critics worry that the cumulative effects of numerous small dams will stifle river systems and fish populations. O'Keefe and other opponents believe new hydroelectricity should come instead from efficiency upgrades and the addition of turbines to existing dams.

Dam operators are increasing capacity at existing sites and looking into the 97 percent of dams in the country that don't have hydroelectric works. But efforts like those of the Snohomish utility district are still important, says National Hydropower Association president Andrew Munro. "We can double U.S. water-power resources (currently 95,000 megawatts) without large dams," he says, as early as 2025 with the right incentives.

In Washington, though, the "right" incentives haven't emerged. The state's renewable energy standard, which requires most energy providers to get 15 percent of their electricity from renewables by 2020, counts power from improvements at existing dams, not new ones. Utility districts supported a bill last year to include new, "low-impact" hydro projects that produce 5 megawatts or less, but it didn't pass.

But the federal renewable energy standard is still up in the air, and other Pacific Coast states welcome new hydro. Oregon, for example, counts new projects up to 50 megawatts if they meet low-impact certification. In January 2008, a San Francisco developer proposed nine new "damless" hydro plants along a 34-mile stretch of the McKenzie River, east of Eugene. The scheme was rejected, but it aroused opposition from paddlers and river advocates, who feared it would harm fish and ruin a popular boating run.

California allows for new small-hydro projects that meet certain criteria, but the state is struggling to meet its goal to produce 20 percent of its electricity from renewable sources by 2010. The utility Pacific Gas and Electric wants to amend the standard to include energy from British Columbia run-of-the-river hydro projects that don't meet California's current renewable criteria. Bowers of the Hydropower Reform Coalition says Washington state legislators are keeping a close eye on California's decision, which could encourage similar projects in Washington, regardless of that state's stricter renewable controls, to serve California's energy needs. It could also inspire a new era of investment and development for small hydro in the Northwest.

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